CNS 1

Question 1

Cerebral cortex

Answer 1

1. Sensory perception
2. Motor control
3. Language
4. Cognitive functions (thinking, memory, willed action, self-awareness: the mind (?))

Question 2

Basal ganglia

Answer 2

1. Movement initiation

2. Inhibition of muscles antagonist to the desired movement

Question 3

Thalamus

Answer 3

Sensory “switchboard” which selects and relays sensory signals to cortex

Question 4

Hypothalamus

Answer 4

1. Homeostasis: temperature control, water balance, hunger

2. Emotions: fight/fright/flight

Question 5

Cerebellum

Answer 5

1. Motor timing, scaling, coordination & learning
2. Balance and gait
3. Eye movements

Question 6

Brainstem

Answer 6

1. Cardiovascular, respiratory, digestive control
2. Sleep/wake cycle, arousal
3. Balance and posture
4. Locomotor initiating centre

Question 7

Spinal cord

Answer 7

1. Locomotor pattern generator

Question 8

Functions of the Limbic System

Answer 8

• Learning
• Emotion
• Appetite (visceral function)
• Sex
• Endocrine integration

Question 9

Meninges:

Answer 9

– Three membranes covering the brain and spinal cord

Question 10

Three membranes

covering the brain and spinal cord:

Answer 10

1. Dura mater → tough outer layer
2. Arachnoid → spidery intermediary mesh
3. Pia mater → delicate inner layer

Question 11

Meningitis

Answer 11

infection of the meninges

Question 12

Cerebrospinal fluid (CSF):

Answer 12

1. Produced in brain ventricles
2. Reabsorbed into venous blood
3. Maintains electrolyte balance around neurons
4. Bathes & supports neural tissue

Question 13

Hydrocephalus (“water on the brain”)

Answer 13

occurs when reabsorption is blocked, CSF accumulates; treated surgically
with drainage tubes

Question 14

Glia → supportive cells in CNS

Answer 14

1. astrocytes
2. Oligodentrocytes
3. Ependymal cells
4. Microglia

Question 15

Astrocytes

Answer 15

a. Physically support neurons (“scaffold”) Astrocyte
b. Form blood-brain barrier
c. Repair: form scar tissue (which unfortunately inhibits regeneration of severed axons)

d. Turnover (recycle) neurotransmitter
molecules

e. Maintain electrolyte balance
([Na +], [K+], [Ca2+], pH, etc.)

Question 16

Oligodendrocytes

Answer 16

Form myelin sheaths that electrically insulate axons

Question 17

Ependymal cells

Answer 17

Produce cerebrospinal fluid (CSF)

Question 18

Microglia

Answer 18

Scavengers: ingest bacteria and debris

Question 19

Brain tumors:

Answer 19

Neutrons cannot divide, so Brian tumours dont develop form neuronal cells

1. Gliomas
2. Meningiomas

Question 20

Blood-brain barrier (BBB):

Answer 20

– Capillaries in CNS are less porous than in rest of body

1. BBB protects neurons from chemical fluctuations & harmful agents
2. Provides oxygen and glucose (Brain does not have glycogen
   stores)
3. Selectively transports molecules needed by brain (eg. Glucose) while excluding harmful ions, hormones, etc. Problem for drug delivery eg. Dopamine in Parkinson’s disease

Question 21

Somatic division controls

Answer 21

voluntary(Skeletal) muscle, autonomic division controls involuntary organs (Heart, gut, bladder etc.)

Question 22

Motor commands conveyed from

Answer 22

CNS to muscles & glands by motor efferent axons

Question 23

Sensory inputs conveyed to

Answer 23

CNS by sensory afferent nerve axons of the peripheral nervous system (PNS)

Question 24

Somatic nervous system

Answer 24

Voluntary command : CNS Move!

Question 25

ANS:

Answer 25

Parasympathetic division: involuntary command (rest and digest)

Question 26

ANS:

Answer 26

Sympathetic division: involuntary command: emergency!

Question 27

Spinal Cord

Answer 27

• Conveys signals from sensory receptors to brain and from brain to muscles

Question 28

Spinal cord contains neuronal circuitry which generates

Answer 28

reflexes and simple, rhythmical movements ( eg. Walking)

Question 29

How many spinal nerves in spinal cord

Answer 29

31 spinal nerves convey signals to and from spinal cord:

• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 1 coccygeal

• Each spinal nerve innervates a specific area of skin (Dermatome) and a specific set of muscles (Myotome)

Question 30

Central ‘grey matter’ in spinal cord tract is comprised of

Answer 30

motoneurons, interneurons, dendrites and axons

Question 31

Surrounding ‘white matter’ in spinal cord is comprised of

Answer 31

bundles of axons (Tracts), conveying sensory signals ascending to brain or motor commands descending from brain

Question 32

When spinal cord is damaged at a given level, sensation from and the motor control of functions

Answer 32

below that level are likely to be abnormal